Sig 229 conversion kit 22LR problems

[red_bailey]

I have a Sig Sauer P229R, ca. 2008-9 manufacture, 9mm, factory stock plain model (no Elite or DAK and such). I picked up a .22LR Conversion Kit on the EE, and I am having trouble making it function.

Well, this is what happens:

When I install the slide and lock it in with the take-down lever, it will not move freely, and binds if I let the recoil spring take it back. You may note the guide rod tends to bend out of position from the pressure; I have attempted to re-position the guide before and after locking, with no satisfaction. Installing the slide without the recoil parts does result in some tightening up when locked down, and the slide alone seems to be just fine.

Apparently Sig uses the same barrel in all their .22 kits, and inserts a different locking lug corresponding to the intended pistol model by pinning it in the bottom of the barrel. Mine is marked ‘29’ on the lug, that should be good. Comparing to other pictures on-line, the lug on mine is correct and pinned in the correct orientation. However, comparing it to the stock 9mm barrel, the lug seems reversed:

You can see my 9mm barrel's lug is flat on the front and round on the rear, whereas the .22LR barrel is round in front, flat in rear. This reverse arrangement allows the conversion barrel to lock in place with the half-moon shape of the take-down pin, something the stock barrel doesn't do:

I haven't shot it, because it doesn't seem like it will operate (safely).

Is the conversion kit defective? Is my pistol defective (it spits 9mm just fine, thanks)? Is this a problem of different versions of Sig's design, where the conversion kit is intended for a different generation of P229? Can I make it work by judicious filing, or changing some small parts (take-down pin on the frame, recoil system on the slide)?

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dmc

 

[Shooting Centre]

All the kits we have in stock have the same orientation of the locking lug.

 

[luke s]

Can you take pics like this of your frame: (this is from my 226)

Take down lever open

Take down lever closed

Take down lever closed, barrel in place

Here are both 226 barrels

The quarter circle shape on the front of the .22 barrel locking lug is where the quarter circle of the take down lever locks the barrel in to the frame, however the barrel is still a bit loose both vertically and horizontally when locked in.
The 9mm barrel on its own does not lock, it can be removed with the take down lever open or closed

I believe the rounded part on your 229 9mm barrel on the rear of the locking lug is likely round to clear the trigger when is is pressed and rotates around the trigger pin. The p226 frame is longer and trigger being pulled does not interfere in this area.

Added video:
[youtube]EPo94Z-eSJw[/youtube]

 

[red_bailey]

Okay, I think I know where the problem is.

Here is the pin for the take-down lever in the open and locked positions:

This is standard; without getting my calipers out and referencing Sig's factory specifications, I can't see anything wrong here. However, when I mount just the .22LR barrel, as in the last picture on my first post, it locks in like in luke s' video (1:25 mark), but I cannot wiggle it one bit like he can. Turning the lever moves smoothly, but tightly. And this is how it looks:

You can see the square chamber block does not sit flush on the locking surface, it is noticeably pushed up in front, which would be the source of the slide interference. This is compounded with the slight downward pressure of the guide rod and spring, magnifying the tension on the slide and causing it to not return to battery.

The solution:

If I file down slightly the area of the barrel lug circled in yellow, maintaining the radius, the barrel should still lock in place but have a bit of play, and not be stressed upwards by a tight fit with the locking pin.

The other possibility is very slightly deepening the slot in the rear of the lug. Thus the whole barrel could move back a hair and not be pressed tightly against the pin. You can see in the final picture that there is plenty of space between the .22 magazine and the feed ramp for the barrel when assembled, so a tiny adjustment shouldn't hinder operation.

Any opinions on whether I am going down the wrong path? Should I simply not do anything to the barrel lug, lest I lose a finger? I'll probably file the round bit a tenth of a millimetre or two, and give just a slight touch to the rear slot. Bad idea? Most people using .22LR conversions on their Sigs are doing it on 226s; who's shooting rim-fire from their 229? Any similar issues?

After much investigation of the pieces and how they fit together, I determined that I had the correct parts, and there was nothing that would cause danger in firing, just failure to cycle and a bit of extra wear in places that were rubbing. I took the whole kit to the range and tried feeding it a single round, which fired and extracted, but as expected it did not spring back to battery. A couple more the same, then I loaded a few rounds in the magazine, fire, extract, but not enough forward motion of the slide to chamber the next round. If I pull the slide back and push it fully forward after each shot, it will feed.

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dmc

 

[drache]

I'll take pictures of my kit as soon as I'm done dinner. My kit works perfectly so far although both the gun and kit were bought from seperate sellers and both were used.

 

[red_bailey]

Solved!

I fixed it.

With the advice and experience of a few people, it seems I'm not the first to encounter too-tight after-market barrels, particularly with German-framed 229s. I guess tolerances in Germany are strict enough that an additional barrel that wasn't fitted to that frame might not be able to drop right in without some adjustment.

Anyway, since nobody else piped up to say I shouldn't do it, I went ahead with careful filing of the barrel lug as I described above. Gave a touch to the rear slot, and filed the front curve in steps until I could lock it in and wiggle it a bit side-to-side and just a hair vertically. The chamber block is still not sitting flush on the locking surface; the barrel is still pushed up when I lock the take-down lever, but I didn't want to go too far. For best performance, should I actually file it until the chamber bottom is completely flat on the ledge in the frame?

With the whole slide mounted, it now springs smartly as it should. Feeds dummy rounds, so I took it to the range, and it all worked smoothly. Ate a box of 100 Mini-Mags with no failures to feed or eject. All shots on paper, I just haven't adjusted the sights. Now I have to get it to point where I'm hitting.

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dmc

 

[drache]

Congrats Red!

 

[luke s]

I am actually wondering if the .22 barrel sits on the locking block after it is in battery, dont think there is a way to tell since that area is covered by the slide